PVP K90 polyvinylpyrrolidone Luvitec K90

PVP K-90 can be used as a stabilizer for glucose (blood sugar) testing, encapsulation - sustained-release agent; Adhesive, stabilizer, protective colloid, film forming agent.

Luvitec series PVP has excellent compatibility, it can coexist with many products in the system, such as: salts, pigments, active ingredients, plasticizers, fungi, blood.

PVP is easily soluble in water, alcohol, amine and halogenated hydrocarbons, but insoluble in acetone, ether and so on. It has excellent solubility, biological compatibility, physiological inertness, film forming, membrane protection ability and the ability to compound with a variety of organic and inorganic compounds, and is stable to acid, salt and heat, so it has a wide range of uses. Used to absorb phenols and tannins from water extracts to purify plant enzymes. Used as a chromatographic adsorbent to separate aromatic acids, aldehydes and phenols. Used for clarification of beer and wine.

Action mechanism

Stabilizing and protective effects

Enzyme/protein stabilizer: Through the coating of polymer chains, fixed glucose oxidase, peroxidase and other biological molecules, to prevent their inactivation due to temperature, pH fluctuations or mechanical shear force.

Protect colloid: inhibit the aggregation of nanoparticles (such as colloidal gold, quantum dots), and maintain the dispersion and signal stability of labeled probes.

Film formation and slow release function

Film forming: A dense film is formed on the surface of the test strip or sensor to protect the active ingredient (such as enzymes, antibodies) from environmental interference (such as oxidation, humidity changes).

Slow-release carrier: The release rate of the reagent is controlled through physical embedding (such as the gradual release of glucose oxidase in the blood glucose test paper, extending the reaction window).

Adsorption and purification

Interference adsorption: combined with phenols, tannic acid and other impurities in the sample, reduce the interference to the detection reaction (similar to the purification principle of plant enzymes).

Chromatographic separation aid: Adsorption of aromatic acids in the chromatographic medium to improve the separation efficiency of target molecules.

Application scenario

Blood glucose detection

Enzyme stabilizer: Used for immobilization of glucose oxidase (GOD) or hexokinase (HK) to prevent enzyme inactivation (such as blood glucose test strip core layer).

Reaction layer film formation: A uniform film is formed on the surface of the test strip to ensure adequate contact between the enzyme and the sample and to control the reaction rate.

Immunochromatography and ELISA

Marker protection: Stabilizes colloidal gold/fluorescent microglobule-labeled antibodies to prevent aggregation or precipitation during storage.

Blocking fluid: Blocks non-specific sites of nitrocellulose membranes to reduce background signals (especially for high viscosity samples such as whole blood).

Molecular diagnosis

Nucleic acid extraction: adsorption of polysaccharides, polyphenols and other inhibitors in samples to improve PCR/qPCR amplification efficiency.

CRISPR assay: Stabilizes Cas protein-guide RNA complexes to enhance the stability of gene-editing reagents.

Biochemical detection

Enzymatic reaction system: As a stabilizer of HRP (horseradish peroxidase) or ALP (alkaline phosphatase), prolonging the color development time of the substrate.

Microfluidic chip: Improve the wettability of hydrophobic channels and reduce liquid flow resistance.

Usage amount

Conventional concentration range

Enzyme stabilizer: 0.5%-2% (need to verify the effect on enzyme activity).

Test strip film: 1%-3% (dissolved in water or ethanol after coating dry).

Sealer/diluent: 0.2%-1% (such as 0.5%-1% in ELISA sealer).

Interference adsorption: 2%-5% (mixing with sample pretreatment solution and centrifugation to remove precipitation).

Dissolution method

Direct dissolution: easily soluble in water and ethanol, need to be stirred slowly to avoid agglomeration (high molecular weight PVP K-90 dissolution time is longer).

Premixed storage: It is recommended to prepare 5%-10% reserve solution, refrigerated storage and avoid microbial contamination.

Matters needing attention

Sealed and moisture-proof store in a cool and dry place (15-25 ° C recommended) to avoid moisture agglomeration or microbial breeding.

Long-term storage may be slightly yellowed, but does not affect function (avoid light).

Temperature sensitivity: High temperature (>70℃) may lead to molecular chain fracture and loss of film formation.

pH compatibility: Stable in pH 3-10 range, may degrade under strong acid/base conditions.

Material compatibility

Plastic containers: Long-term contact may swell polystyrene (PS) containers, it is recommended to use glass or stainless steel containers.

Protein interference: Excess may adsorb antigens/antibodies, and the concentration needs to be optimized through pre-experiments.

incompatibility

Strong oxidizing agent: Oxidation reaction may occur with high concentration ammonium persulfate, sodium hypochlorite, etc.

Polyvalent cations: Combined with Ca² +, Mg² +, etc., may form gels or precipitates.

Frequently Asked Questions (FAQ)

Q: What is the difference between PVP K-90 and K-30?

A: K-90 has higher molecular weight (about 1,000,000), stronger film formation and greater viscosity, suitable for slow release systems requiring high mechanical strength; K-30 (molecular weight about 40,000) is more focused on dispersion and solubilization.

Q: Why do I need to use PVP K-90 in blood glucose test strips?

A: Its high viscosity and film formation can accurately control the thickness of the enzyme reaction layer, ensure stable and uniform release of glucose oxidase, and improve the consistency of detection.

Q: How to deal with gelatinous substances when dissolved?

A: Due to high molecular weight, it is necessary to extend the stirring time (or heating to 40-50℃) to avoid excessive local concentration leading to incomplete dissolution.

Q: Does it affect the electrochemical sensor performance?

A: Low concentration (<0.5%) has no significant interference, but high concentration may hinder electron transfer due to film formation, and the dosage needs to be optimized.

Q: Can you replace PEG (polyethylene glycol) as a stabilizer?

A: Experimental verification is required. PVP K-90 has different stabilization mechanisms for proteins (hydrogen bond vs. Spatial rejection), may be more effective against specific enzymes.

Luvitec  is a trademark of BASF